I was tutored at the knee of a grizzled old Sioux (Lakota) Tribal Leader who explained the pictographs in a "Winter Count" painting, a Tribal Calendar marking the most important event of the year. One of the years show buffalo carcasses at the bottom of a cliff sometime near the start of the 19th century. The old tribal leader explained that the elders had admonished their young repeatedly not to harvest buffalo in this wasteful manner. But the herds seemed so thick and the chore of shooting a dozen or so buffalo to supply the tribal needs with bows seemed so troublesome. In the end, the admonishments of the elders (who had seen the herds increase and decrease in cycles) were not heeded.
Louis and Clark made their journey began in 1804, they describe quite well the carcasses off the cliff.... I believe there are other known references to such finds by other explorers as well, but I will stick to just Louis and Clarks accounts.
I will concede that the native americans did not stampede herds over cliffs from the begining of time... they lacked the techonology to do so. It was not until the horse was introduced to the americas and mastery of horsemanship by the native americans that they had the technological ability to create and guide a stampede to a cliff.
I will not dispute your claims that elders councilled against such behaviors... I have no way to know if they did or did not. The point I am trying to make is simple that the native americans were not the ideolized and romanticized peoples that political correctness has made them out to be.
Sadly factual truth is lost to romanticized political correctness, just as Pirates have been romanticized as well... they were far worse than even the most savage of Indian tribes, but today most people look at them as just likeable cads.